Question about unlocked N1

If I were to buy the new AT&T compatible version of the Nexus One and insert my own SIM card (I am currently on a shared plan, if that matters), would the $30/month plan be my only choice for unlimited data, or would I be able to choose a cheaper unlimited plan, like that of a feature phone, which is I believe only 10 or 15 per month on att? I don't know much about unlocked phones so I wanted to make sure about the data plan before making the $529 purchase.

So basically, with an unlocked att Nexus One, if I want unlimited data, would I be stuck with the $30/month smartphone plan or could I purchase $15/month feature phone plan?

I would think that since it is unlocked, I could (should) have the freedom to choose either plan, but I am not sure.

AT&T requires you to purchase $30/month data plan for "any" smartphone - it's their policy. Although you can purchase $15/month plan for your nexus one, AT&T will get you(they will check the IMEI) and update your plan to $30/month automatically with a text message notice.

Your logic presents a slight fallacy. If the $10/15 data plan for feature phones is unlimited, so is the $30 smartphone plan, why would you EVER choose the more expensive one? But to answer your question, YES you can get the $15 one as long as you don't register your device, however if you try to use data you'll get billed on a Pay per use basis because the data transfer is different than that on feature phones.

If you check the AT&T section of Howard Forums, you'll find that AT&T seems to know the IMEI of Nexus One phones and will automatically send you a message stating that you require the $30 smartphone plan. You don't even need to register the phone. AT&T knows.

As for not using data: All Android phones use data the moment you turn them on because of the requirements of apps. The only way to avoid this are (1) NOT to set the APN address of the carrier (AT&T), 2 use an app called APNdroid (that can turn on and off the APN), or 3 tell AT&T to block data (I am not sure if that is allowed anymore). But if you do that, why even buy a smartphone.

Because you can use wifi and you can still place a data block. That being said I and many other people have been on medianet for many an unbranded smartphone with no issues. Up to now the only people who have had this issue are those who tried to use a subbed handset, sadly however it does appear that for whatever reason AT&T is going after the N1 owners. Some report no issues but many are getting the dreaded text message (We have figured out that you are not on the correct plan and have changed it to the proper smartphone plan/words to that effect) so I would be prepared for that possibility. You stand a much better chance of sliding if you start data on a feature phone and then moving your sim over after a few days. You can always try medianet and then block data and go to wifi after the fact if you get the message. I suspect however that if you spend much time with a free range smartphone you might find yourself willing to pony up the extra 15 after you get kneecapped.